Bunn-O-Matic came out with a different drip-brew machine. In this type of coffeemaker, the machine uses a holding tank or boiler pre-filled with water. When the machine is turned on, all of the water in the holding tank is brought to near boiling point (approximately 200–207 °F or 93–97 °C) using a thermostatically-controlled heating element. When water is poured into a top-mounted tray, it descends into a funnel and tube which delivers the cold water to the bottom of the boiler. The less-dense hot water in the boiler is displaced out of the tank and into a tube leading to the spray head, where it drips into a brew basket containing the ground coffee. The pourover, water displacement method of coffeemaking tends to produce brewed coffee at a much faster rate than standard drip designs. Its primary disadvantage is increased electricity consumption in order to preheat the water in the boiler. Additionally, the water displacement method is most efficient when used to brew coffee at the machine's maximum or near-maximum capacity, as typically found in restaurant or office usage. In 1963, Bunn introduced the first automatic coffee brewer, which connected to a waterline for an automatic water feed.
For example, if your coffee tastes a bit salty or sour, the grounds are under-extracted, which can be remedied by a finer grind. But what if only some of your grounds are too coarse, and others are too fine – and maybe some are just right? Having uniform grind size throughout your brew basket makes it easier to isolate and adjust this variable in order to get the level of extraction you want. The only way to achieve that is with a burr grinder. Miller — as well as a handful of our other experts — recommends the Barazata Encore Coffee Grinder ($129).
The Mr. Coffee Optimal Brew coffee maker System has a highly modular design, with its rectangular water reservoir easily sliding in and out of the chassis. For those who only want a cup of basic coffee, you will find that the Mr. Coffee Optimal Brew coffee maker System will do that very well – its "brew now" button is found on the front of the machine.
Where MistoBox really shines is in its efficiently designed website and deep customization. If you want to, you can sign up for a scheduled delivery of curated espresso blends or single origin coffees and just let it ride—no input is necessary beyond the initial question of what kind of roast you like. But if you want to get a little more involved, you can rate each coffee you receive to refine future shipments or—if you want to take the future into your own hands—curate your own list of upcoming beans with a feature MistoBox calls the "Brew Queue." The number of choices is dizzying, and there are plenty of user reviews to guide your way thanks to a very active community.
The tall tower is fixed on a rectangular base, with a water tank that looks something akin to a trapezoid. The hard plastic funnel allows your favorite paper filters to fit inside of it. It is recommended that you use type 4 paper filters, however. You also have the option to use permanent gold filters if you want to move away from reoccurring costs.
It can take a little while to get to know the ins and outs of a new coffee maker. In CR’s labs, each drip coffee maker we test brews roughly 65 cups by the time our engineers are through with it. And brewing is just one of many aspects we look at. We test for handling and convenience, too, so you can choose a model that helps you sail through morning madness.